Vacuum processing machine for aluminizing headlamp reflectors

ABSTRACT

A vacuum processing machine for continuously aluminizing headlamp reflectors wherein a reciprocating transfer shuttle and a transverse transfer carriage cooperate to alternately shift finished and unfinished reflectors between a loading and unloading station at one end of the machine to a high vacuum processing chamber at the other end of the machine for application of an aluminized reflective coating. For each forward stroke of the transfer shuttle, unfinished reflectors are shifted toward the processing chamber through a plurality of holding chambers of progressively increasing vacuum. For each reverse stroke, finished reflectors are carried from the processing chamber through the holding chambers for exit to atmosphere at the unloading station.

[451 Feb. 20, 1973 [54] VACUUM PROCESSING MACHINE FOR ALUMINIZINGHEADLAMP REFLECTORS [75] Inventors: Donald R. Boys; Ernest W. White,

both of Anderson, Ind.

3,469,560 9/1969 Bukkila Cl; al ..l l8/49 X Primary Examiner-MorrisKaplan Attorney.l. L. Carpenter et al.

[57] ABSTRACT A vacuum processing machine for continuously aluminizingheadlamp reflectors wherein a reciprocating transfer shuttle and atransverse transfer carriage cooperate to alternately shift finished andunfinished reflectors between a loading and unloading station at one endof the machine to a high vacuum processing chamber at the other end ofthe machine for application of an aluminized reflective coating. Foreach forward stroke of the transfer shuttle, unfinished reflectors areshifted toward the processing chamber through a plurality of holdingchambers of progressively increasing vacuum. For each reverse stroke,finished reflectors are carried from the processing chamber through theholding chambers for exit to atmosphere at the unloading station.

6 Claims, 13 Drawing Figures [73] Assignee: General Motors Corporation,

Detroit, Mich.

[22] Filed: July 30, 1971 [211 App]. No.: 167,755

[52] U.S. Cl.- ..ll8/49, 198/19 [51] Int. Cl ..C23c 13/10 [58] Field ofSearch... ..1 18/49, 49.1, 48, 49.5, 6, 118/50, 50.1, 423, 425,500, 503;198/19 [56] References Cited UNITED STATES PATENTS 2,730,987 I 1/1956Nelson ..l l8/49 3,037,607 6/1962 l-lighfield et al. ..l98/19 3,086,8824/1963 Smith, Jr. et al ..1l8/49.1 X

PATENTED r1820 9. 3.717. 1 19 AT TORNEY VACUUM PROCESSING MACHINE FORALUMINIZING HEADLAMP REFLECTORS The present invention relates to anapparatus for transferring articles to a processing station on acontinuous basis and, in particular, to a vacuum processing machine forcontinuously transferring unfinished reflectors to processing stationfor aluminizing and subsequently returning finished reflectors to theambient environment.

Current production techniques for applying a reflective coating toarticles such as headlamp reflectors involve placing the unfinishedreflectors in a chamber, closing and sealing the chamber, evacuating thechamber to a high vacuum, and performingthe reflectorizing process.Thereafter, the chamber is vented and opened, and the finishedreflectors are removed. Quite obviously, the production rate with thismethod is directly related to the pump down time for evacuating thechamber plus the processing time for applying the reflective coating.Generally, the pump down time considerably exceeds the processing time.

In an effort to increase the production rate of such parts, dynamicsystems using an air-to-air system transfer of parts have been proposedwherein the unfinished parts pass through a series of chambers to aprocessing station and, after processing, move through a separate seriesof chambers and exit the machine at atmospheric conditions. Typically,the unfinished parts are loaded onto a unidirectionally moving conveyorsystem and fed through progressively increasing vacuum chambers viapressure locks to a high vacuum chamber for the reflectorizingoperation. The finished parts are then routed from the work chamberthrough a second series of chambers with increasing pressureenvironments for subsequent exit to the ambient environment. However,the multiplicity of serially connected chambers requires considerablelength, and a large and complex vacuum system for maintaining therequisite vacuum conditions.

The present invention contemplates a vacuum processing machine wherein asingle series of vacuum chambers are simultaneously used for introducingunfinished parts to the processing station and for removing finishedparts to an unloading station. This feature is accomplished by areciprocating transfer shuttle which extends through a plurality oflongitudinally aligned, independently sealed chambers. The transfershuttle includes carrier nests registering in its extended position andits retracted position with adjacent vacuum chambers. A transfercarriage at the work handling end and in each of the chamberstransversely reciprocates at each end of the shuttle stroke to remove afinished article from the carrier nest to a holding platform fromtemporary storage and, at the same time, place an unfinished article onthe carrier nest for advancement toward the processing station.

At the work processing station, the transfer carriage, during eachforward stroke of the transfer shuttle, moves an unfinished article toone of two aluminizing stations and simultaneously loads a finishedarticle onto the vacated carrier nest. During the reverse stroke of thetransfer shuttle, the processing or aluminizing is performed on thereflector. At the end of the next forward stroke, the coated article isremoved from the first aluminizing station and an unfinished articletransferred to the second aluminizing station.

Thus, for each forward stroke of the shuttle, an unfinished part iscarried forward for processing. For each reverse stroke, a finished partis carried away from the processing station. The net effect of thisarrangement is to reduce the overall length of the processing machine bytransferring finished and unfinished parts through common chambers forloading and unloading the parts at a common location. Thus, separatereturn chambers are not necessary thereby resulting in a large reductionof system length and associated equipment for maintaining the vacuumstherewithin. Additionally, the production rate is solely controlled bythe aluminizing rate and independent of the pump down time.

Accordingly, an object of the present invention is to provide anapparatus for bidirectionally transferring articles from a loading andunloading station at one end to a work station at the other end.

Another object of the present invention is to provide a processingmachine wherein a reciprocating transfer mechanism shifts unfinishedarticles toward a processing chamber during the forward stroke andcarries finished articles away from the processing chamber during thereverse stroke.

A further object of the present invention is to provide a processingmachine for continuously aluminizing headlamp reflectors that has aproduction rate substantially independent of the pump down time.

Still another object of the present invention is to provide a vacuumprocessing machine wherein unfinished articles enter at ambientconditions and are transferred through a group of vacuum chambers to aprocessing station, and finished articles are returned to the ambientatmosphere through the same chambers along a reversely parallel path.

A further object of the present invention is to provide a vacuumprocessing machine for continuously transferring unfinished headlampreflectors to an aluminizing station for treatment and subsequentlyreturning the finished reflectors to an ambient environment wherein areciprocating transfer shuttle accepts unfinished reflectors at one endof the machine and, during each forward stroke of the shuttle,sequentially advances the reflector along a series of vacuum holdingchambers toward the aluminizing station while, during each reversestroke, the transfer shuttle returns finished articles through the sameholding chambers for ultimate exit at the entrance end of the machine.

These and other objects will be apparent to one skilled in the art uponreading the following detailed description, reference being made to theaccompanying drawings showing a preferred embodiment in which:

FIG. 1 is a plan view of a vacuum processing machine made in accordancewith the present invention illustrated without the transfer carriage;

FIG. 2 is a side elevational view of the vacuum processing machine ofFIG. 1;

FIG. 3 is an enlarged view taken along line 33 of FIG. 1;

FIG. 4 is a view taken along line 4-4 of FIG. 3;

FIG. 5 is a view taken along line 5-5 of FIG. 3;

FIG. 6 is an enlarged view of the cam drive for the transfer carriage;

FIG. 7 is a partially sectioned view of a headlamp reflector;

FIG. 8 is an enlarged view taken along line 8-8 of FIG. 1',

FIG. 9 is a view taken along line 9-9 of FIG. 8;

FIG. 10 is an enlarged view taken along line ll0 of FIG. 1;

FIG. 11 is a view of the aluminizing station in the processing chamber;

FIG. 12 is a schematic vacuum pumping diagram for the vacuum processingmachine; and

FIG. 13 is a schematic flow diagram showing the I routing of reflectorsthrough the vacuum processing machine.

Referring to FIGS. 1 through 3, there is shown an airto-air vacuumprocessing machine comprising four serially connected longitudinallyaligned vacuum holding chambers 12, 14, 16, 18, and a work processingchamber 20. In a manner hereinafter described, the machine 10bidirectionally transfers finished and unfinished articles such asheadlamp reflectors by means of a reciprocating transfer shuttle 22between a loading station 23 and an unloading station 24 at the frontend of the machine and a processing station 25 in the processing chamber20.

More specifically, the vacuum processing machine 10 includes a vacuumenclosure 26 having sidewalls 27, front and rear end walls 28, 29, andtop and bottom walls 30, 32 respectively. The enclosure 26 includestransverse internal divider walls 34 which cooperate with theaforementioned walls to establish the holding and processing chambers. Aplurality of coaxially aligned cylindrical support sleeves 36 extendthrough openings in the divider walls 34 and the end wall 28. As shownin FIGS. 4 and 5, the support sleeves 36 are fixedly mounted on thedivider walls 34 by flanges 37.

Referring to FIGS. 1 and 2, the transfer shuttle 22 is reciprocablysupported at intermediate positions by the sleeves 36 for bidirectionalaxial movement between an extended position and the illustratedretracted position. The shuttle 22 includes a pair of support shafts 38at the ends thereof which are supported by slide bearing assemblies 39,40 positioned adjacent the stations 23, 24 and the station 25,respectively.

The transfer shuttle 22 is generally in the form of an elongatedcylindrical piston and includes five transverse triangular carrier nests41. As shown in FIG. 4, each carrier nest 41 includes a horizontal base42 and converging sides 43 which terminate at an upwardly openingtransverse slot 44. The nests 41 are of sufficient size to accommodateheadlamp reflectors of varying sizes. The nests 41 are longitudinallyspaced along the transfer shuttle 22 on the same centers as the centerdistance between the individual chambers. Thus, referring to FIG. 2wherein the transfer shuttle 22 is shown in the retracted position, thecenterline 46 of the entrance carrier nests 41 will advance a distance Dto the centerline 48 of the chamber 12 during the forward stroke of thetransfer shuttle 22. The remaining carrier nests will advance a distancetoward the next adjacent chamber during the aforementioned stroke. Ateach extreme of movement, therefore, the carrier nests 41 will registerand be transversely aligned with the centerlines of the respectivechambers 12 through inelusive.

The front support shaft 38 of the transfer shuttle 22 is reciprocablyjournaled by the aforementioned bearing 39 at a support block 52. Adouble-acting hydraulic cylinder 56 is mounted on the support block 52and includes a forward projecting piston rod 58. The shaft 38 and thepiston rod 58 are operatively interconnected by a cross member 60. Thehydraulic cylinder 56 has a forward and reverse stroke equal to thedistance D between centers of the carrier nests 41. Upon suitableenergization, the hydraulic cylinder 56 will drive the transfer shuttle22 between the illustrated retracted position and the extended position.

Referring to FIGS. 8 and 9, the unloading station 24 and the loadingstation 23 are transversely spaced on either side of the transfershuttle 22 at the front end of the machine 10. Unfinished and finishedparts are transferred to and from handling platforms 63 and 64 carriedby the end wall 28. The subject machine is particularly adapted foraluminizing headlamp reflectors of the type shown in FIG. 7. Such areflector 66 comprises a paraboloidal base 67 terminating with anannular peripheral rim 68 having a center exhaust tube 69. The reflector66 is formed of glass and has an inner surface which receives areflective coating in the manner hereinafter described. By means of atransfer carriage 70, unfinished reflectors are loaded onto a carriernest 41 from the loading platform 63 while finished reflectors aretransferred from the carrier nest 41 to the handling platform 64. Thereflectors may be manually handled at the platforms 6.3, 64 orautomatically handled by conventional devices such as a conveyor orindexing head.

The transfer carriage 70 comprises a transfer slide 72 including a pairof laterally spaced depending legs 73, 74 and a guide assembly 75 whichis slidably supported for transverse reciprocating movement on a pair ofguide bars 76. The transfer slide 72 is operatively connected at theguide assembly 75 to a drive linkage 77 including a tie rod 78 and adrive lever 80. The drive lever 80 is pivotally supported in anintermediate position by a shaft 82 carried on a bearing block 84 at theend wall 28. The lower end of the drive lever 80 is pivotally connectedto a connecting rod 85 which is driven by a cam drive hereinafterdescribed. For every stroke of the transfer shuttle 22, the cam drivereciproeates the transfer slide 72 with respect to the carrier nest 41.

In operation, the transfer slide 72 has a first position wherein bothlegs 73, 74 are positioned over the loading platform 63 and a secondposition wherein the leg 73, 74 are positioned on either side of theshuttle 22. More particularly, during initial transverse movement to theleft as driven by the linkage 77, the leg 73 engages the rim of anunfinished reflector to shift the latter across the loading platform 63and into the carrier nest 41. Concurrently therewith, the other leg 74engages the reflector to move the latter from the carrier nest 41 to theunloading platform 64. During the forward stroke of the transfer shuttle22, the transfer slide 72 dwells in the last mentioned position with thelegs 73, 74 straddling the transfer shuttle 22. At the end of theforward stroke, the drive linkage 77 is actuated to shift the transferslide 72 to the right for acceptance of an unfinished reflector andsubsequent loading on the shuttle upon completion of the rearwardstroke.

Referring to FIGS. 3 to 6, reflectors are shifted to and from thecarrier nest 41, to the holding chambers 12 through 18 by transfercarriage 100. Each transfer carriage 100 generally comprises a transferslide 102 and a drive linkage 104. The transfer slide 102 includes aguide assembly 106, and three downwardly depending workpiece engaginglegs 108, 110, and 112. The guide assembly 106 is slidably supported ona pair of transverse guide bars 114 for transverse reciprocatingmovement with respect to the transfer shuttle 22. The legs 108, 110, and112 are transversely spaced a distance greater than the diameter of theshuttle 22 and define therebetween a pair of work receiving openings 120and 122.

The drive linkage 104 includes a tie rod 124 connected at one end to theguide assembly 106 and at the other end to a drive lever 126 which issupported on a drive shaft 128 which extends through the chambers 12through 18. As shown in FIG. 8, the drive shaft 128 has an input end 130projecting from the front end wall 28. A crank arm 132 is connected atone end to the input end 130 and at the other end to a connecting rod134. By a cam operated drive hereinafter described, the crank arm 132rotates the shaft 128 to drive the transfer carriage 100 between twopositions.

Referring to FIGS. 3 through 5, a pair of vertical holding plates 136,138 are supported on a stand 137 carried between the divider walls 34.The plates 136, 138 register with the sides of the carrier nest 41 andare adapted to support a reflector 66. In the illustrated firstposition, the opening 120 is positioned over the left or unfinished sideholding plate 138 while the other opening 122 registers with the carriernest 41 with the legs 110, 112, straddling the transfer shuttle 22. Atthe other position, the opening 120 registers with the carrier nest 41with its legs 108, 110 straddling the transfer shuttle 22 while theother opening 122 is positioned over the right or finished side holdingplates 136.

The cam drive means for the linkage 104 translates the slide 102 at theend of each transfer shuttle stroke. Thus, at the end of the reversestroke and prior to the forward stroke of the transfer shuttle 22, thelinkage 104 drives the transfer slide 102 to the right such that thecentral leg 110 shifts a finished reflector onto the holding plate 136and the left leg 108 engages the rim of an unfinished reflector to movethe latter from the holding plate 138 to the carrier nest 41. The slide102 dwells in this position during the forward stroke of the transfershuttle 22. At the end of the stroke, the drive linkage 104 shifts theslide 102 to the left and the central leg 110 moves the unfinishedreflector onto the holding plate 138 and the aforementioned finishedreflector from its holding position on the holding plate 136 to thecarrier nest 41.

Referring to FIG. 10, the processing chamber 20 includes a transfercarriage 140 which is substantially identical to the aforementionedcarriages 70 and 100. The carriage 140 comprises a transfer slide 142and a drive linkage 144. The transfer slide 142 includes a guideassembly 146 and three downwardly depending workpieces engaging legs148, 150, and 152 which are mutually transversely spaced a distancegreater than the diameter of the shuttle 22. The guide assembly 146 isslidably supported on a pair of guide shafts 154 for transversereciprocal movement with respect to the transfer shuttle 22. The drivelinkage 144 includes a tie rod 156 pivotally connected at one end to adrive arm 158. The other end of the tie rod 156 is connected to theguide assembly 146. The lower end of the drive arm 158 is keyed to ashaft 160 which extends longitudinally through the chambers 12 through20 and has an input 162 extending at the front of the machine (FIG. 8).The input 162 is operatively connected to a connecting rod 164 by acrank arm 166. The connecting rod 164 is operatively reciprocated by acam drive (not shown) in a manner hereinafter described.

Referring to FIGS. 10 and 11, a pair of aluminizing stations and 172 arespaced on either side of the transfer shuttle 22. Both aluminizingstations are identical and a further description will be given withreference to the aluminizing station 170. More particularly, eachaluminizing station includes an apertured processing platform 174 havinga cylindrical sleeve 176 defining a circular aluminizing opening 178. Apivoting shield 180 is mounted on a support platform 182 carried on theside wall 29. A drive linkage 184 operatively connects the shield 180 toan air operated rotary actuator 186. Upon energization of the actuator186, the linkage 184 pivots the shield 180 to cover or uncover theopening 178.

A resistance heated aluminizer is supported on the platform 182 andincludes a crucible 192 and a pair of wire feeding mechanisms 194, thelatter of which serve to feed a supply of aluminum wire to the crucible192 as regulated by drive means 196 including a motor 198.

The operation of the aluminizer 190 is basically conventional in thataluminum wire feed into the crucible 192 is melted and resistance heatedso as to be vaporized. In the present instance, when an unfinishedreflector is positioned over the opening 178, the shield 180 is pivotedaway from the sleeve 176 and the aluminum vapor diffuses upwardly andcoats the inner surface of the reflector 66 to thereby provide areflective coating.

Unfinished reflectors are alternately transferred to the aluminizingstations 170, 172 as controlled by the transfer carriage 140. Duringeach forward stroke of the transfer shuttle 22, an unfinished reflectoris advanced toward the processing chamber 20. Assuming an unfinishedreflector is located on the carrier nest 41 at the processing chamber20, the linkage 144 will be automatically energized at the completion ofthe forward stroke. Thereupon, the slide 142 will be shifted to the leftand the leg 150 will move an unfinished reflector onto the processingplatform 174. The carriage 140 will dwell in this position duringreverse stroke of the transfer shuttle 22. Concurrently therewith, thealuminizing stations 170 will be energized in the manner described aboveto apply a coating to the reflector.

In the present machine, the cycle time of the transfer shuttle 22 isequal the processing time for applying the coating to the cycle to thereflector. Therefore, the carriage dwells in this position during thereverse stroke and the subsequent forward stroke. At the end of the nextforward stroke, the drive linkage 144 is actuated to shift the slide 142to the right whereby leg 150 shifts a newly advanced unfinishedreflector to the platform 172 and the leg 148 shifts a coated reflectoronto the carrier nest 41. In other words, the carriage 140 operates atone-half the frequency of the transfer carriages 70 and 100.

Referring to FIG. 2, the drive means for the carriages comprises anelectric motor 200 mounted on a pedestal 202 connected to the base ofthe machine. A drive shaft 204 carries three output cams 206, 208 and210 and is operatively connected to the output of the motor 200. Thecams 206, 208 and 210 respectively operatively engage three followerarms 212, 214,. and 216 which are pivotally connected at their lowerends to a shaft 218. The upper ends of the follower arms 212, 214, 216are respectively operatively connected with the connecting rods 85, 134,164 which operate the drive shafts of the transfer carriages 70, 100,140.

Referring to FIG. 6, wherein the cam drive for the processing chamber isshown, the cam 210 includes a rise and fall cam surface 220. Thefollower arm 216 includes a follower pin 222 which is continuouslybiased against the cam surface 220 by a tensioned spring 224 extendingbetween the upper end of the arm 216 and the bottom wall 32. The cam.surface 220 comprises dwell sectors letter A (Alpha) and B (Beta)corresponding to the dwell time of the transfer slide 142 over theprocessing stations 170, 172 and intermediate actuating sectors 1(Gamma) and A (Delta) having gradually changing cam profiles whichtranslate the carriage 140 between the aforementioned positions duringdwell time of the transfer shuttle 22.

More specifically, the output speed of the shaft 160 is equal to thecycle time of the transfer shuttle 22. The dwell time presented by thesectors A and B is equal to the stroke time of the transfer shuttle. Thetime presented by the actuating sectors A and F is equal to the dwelltime of the transfer shuttle 22. Accordingly, during rotation of the cam210 through sector A, the follower arm 216, the connecting rod 164 andthe shaft 160 remain stationary with a reflector being positioned at analuminizer 190. As the follower pin traverses sector A, the crank arm166 is pivoted counterclockwise under the influence of spring 224thereby rotating shaft 160 in the same direction. This rotates thelinkage 144 to the right (FIG. 10) thereby shifting a finished reflectoronto the carrier nest 41 and a newly advancing unfinished reflector ontothe processing station 172. During sector B, the transfer shuttle 22reciprocates through a rearward stroke and forward stroke while acoating is applied at station 172. During sector I the cam 210 willdrive the follower arm 216 and the crank arm 166 in a clockwisedirection thereby shifting the slide assembly to the left. This actionremoves a coated reflector from the station 17 2 to the carrier nest 41and shifts the uncoated reflector from the carrier nest 41 to thestation 174.

Inasmuch as the carriages for the holding chambers 12 through 18 and theloading and unloading stations 23, 24 operate at twice the frequency ofthe processing chamber 20, a two cycle rise and fall cam profile isprovided for these cams. Accordingly, the cams will have the four dwellsectors each corresponding to the stroke time of the shuttle 22. The tworise and the two fall sectors will each correspond to the dwell time ofthe transfer shuttle 22. For achieving this interaction, conventionalcontrol means are provided to coordinate the operation of the hydrauliccylinder 56 and the electric motor 200.

The vacuum system for the aluminizing machine 10 is shown in FIG. 12wherein the designated pumping equipment is attached to the individualchambers through appropriate porting and piping. More specifically, theinitial pump down of all the chambers and maintenance of chamber 12 isprovided by a house vacuum supply 240. The chamber 14 is provided withcentrifugal blower 242 in series with a mechanical vacuum pump 244. Thechamber 16 is provided with centrifugal blower 246 in series withmechanical vacuum pump 248. Chamber 18 is provided with a diffusion pump250 and a mechanical vacuum pump 252. The vacuum in processing chamber20 is maintained by a pair of parallel diffusion pumps 254 and 256connected in series with a vacuum pump 258. Preferably, theaforementioned pumping equipment should be designed to provide thefollowing environmental conditions:

STATION VACUUM Chamber 12 I00 Torr Chamber 14 l X 10" Torr Chamber 16 IX 10* Torr Chamber 18 l X 10" Torr Chamber 20 l X 10 Torr The routing ofreflectors through the machine is shown in FIG. 13 wherein parts areprocessed by sequential entry of unfinished parts from the loadingplatform 63 to the transfer shuttle 22 At the end of each reversestroke, the transfer carriage shifts an unfinished reflector to the endcarrier nest 41 on the transfer shuttle 22. The transfer shuttle 22 thenreciprocates forwardly to its extended position at which time theholding chamber transfer shuttle shifts the unfinished reflector to astorage or holding position on the platform 138 where it remains duringthe reverse shuttle stroke. At the end of this stroke, the transfershuttles 70, 100 are jointly actuated to shift unfinished reflectorsfrom the platforms 63 and 138 onto the carrier nest 41. Theaforementioned sequence is sequentially repeated until unfinishedreflectors are resting on each platform 138. During the next forwardstroke of the transfer shuttle 22, the unfinished reflector is depositedon a pedestal at one of the aluminizing stations 170, 172. As previouslymentioned, during the subsequent reverse and forward strokes, areflective coating is applied to the unfinished reflector. Concurrently,during the last mentioned forward stroke, another unfinished reflectoris shifted from chamber 18 toward the other processing chamber 20. Atthe end of this stroke, the carriage 140 is actuated to remove thecoated reflector to the carrier nest 41 and the advancing unfinishedreflector to the other aluminizing station. During the next reversestroke, the coated reflector is carried toward chamber 18 and at the endthereof is shifted to the holding platform 136 while unfinishedreflectors are advanced to the carrier nest from the opposite platform136. Thereafter, finished reflectors are sequentially advanced towardthe unloading platform 64 during each reverse stroke of transfer shuttle22 and during each forward stroke, unfinished reflectors are movedtoward the processing station 20. Thus, the finished andunfinishedreflectors bidirectionally shift along the machine in parallelpaths for processing at one end and common exit and entry at the otherend.

In the subject system, the largest cause of variance in environmentalpressure conditions results from fluid flow due to the volume of thecarrier nest 41. However,

the sizes of the nests 41 are sufficiently small in comparison with thevolume of the chambers so that this fluid transfer does not materiallyaffect the environmental conditions in the chambers. Accordingly, theprocessing chamber is maintained at a vacuum suitable for continuousprocessing such that coating may begin immediately upon arrival ofunfinished parts. Therefore, the production rate of the machine isindependent of pump down time and proceeds solely in accordance with thealuminizing time.

Although only one form of this invention has been shown and described,other forms will be readily apparent to those skilled in the art.Therefore, it is not intended to limit the scope of this invention bythe embodiment selected for the purpose of this disclosure but only bythe claims which follow.

What is claimed is:

l. A transfer apparatus for advancing articles toward and retreatingarticles from a processing operation comprising: a support member; aplurality of stations on said support member including a handlingstation at one end and a processing station at the other end associatedwith the processing operation; a shuttle member extending between saidstations; means for moving the shuttle member between a first positionand a second position; carrier means associated with the shuttle memberfor accommodating said articles, one of said carrier means registeringwith said handling station at said first position for receivingunprocessed articles and for discharging processed articles, another ofsaid carrier means registering with said processing station at saidsecond position for discharging unprocessed articles for a processingoperation and receiving processed articles, and intermediate carriermeans alternately registering with adjacent stations at said positionsfor receiving and discharging articles; first transfer means at saidprocessing station. operable at said second position to dischargeunprocessed articles from and to load processed articles on said carriermeans; second transfer means at the other of said stations, said secondtransfer means operable at said first position to discharge unprocessedarticles from and to load processed articles on said carrier nests, saidsecond transfer means operable at said second position to dischargeunprocessed articles from and to load processed articles on said carriermeans whereby unprocessed articles are alternately advanced along saidstations to said processing station during movement to said secondposition and processed articles are alternately retreated from saidprocessing station along said stations in a reversely parallel pathduring return movement to said first position.

2. An apparatus for processing articles comprising: means forming aplurality of interconnected chambers and having an ambient handlingstation at one end and a pressure regulated processing station at theother end; passage means extending between said chambers; first transfermeans slidably received in said passage means; means for imparting aforward stroke and a reverse stroke to said first transfer means; meansconnected to said chambers for maintaining predetermined pressureconditions therewithin; carrier means associated with said firsttransfer means for accommodating said articles, one of said carriermeans registering with said handling station at the end of said reversestroke for receiving unprocessed articles and dispensing processedarticles, another of carrier means registering with said processingstation at the end of said forward stroke for presenting unprocessedarticles for a processing operation and receiving processed articles;and second transfer means in said chambers operatively associated withsaid first transfer means, said second transfer means being operableafter said forward stroke to transfer unprocessed articles to holdingpositions in said chambers and to transfer processed articles to saidcarrier means, said second transfer means being operable after saidreverse stroke to transfer unprocessed articles from said holdingpositions to said carrier means and to transfer processed articles fromsaid carrier means to said holding positions whereby articles arealternately advanced for processing and unloading during each stroke ofsaid first transfer means.

3. A continuous vacuum processing apparatus for applying a coating to anarticle, comprising: an enclosure having a series of chambers; passagemeans defining an entrance and interconnecting said chambers; pumpingmeans communicating with the chambers for evacuating the latter to apredetermined pressure; a piston member slidably supported in saidpassage means and extending between the chambers; means forreciprocating said piston member relative to the chambers between anextended position and a retracted position; a work station at a chamberremote from said entrance including means for applying said coating toan uncoated article; nesting means on said piston member aligned andregistering with the chambers at said extended position and saidretracted position, one of said nesting means being exposed toatmosphere beyond said entrance at said retracted position for receivingthereat an uncoated article and dispensing therefrom a coated article;transfer means in said chambers operable at said retracted position toshift coated articles from said piston member and shift uncoatedarticles onto said nesting means, said transfer means being operable atsaid extended position to shift uncoated articles from said nestingmeans to said work station and to simultaneously shift coated articlesonto said nesting means, whereby articles are continuously routed to andfrom said work station during each movement of said piston member.

4. A vacuum processing machine for processing articles on a continuousbasis, comprising: an enclosure having an enclosed processing end and anexposed handling end; a plurality of interconnected chambers in saidenclosure including a processing chamber at said processing end; meansconnected to said chambers for maintaining a series of predeterminedpressure conditions therewithin; passage means extending through saidchambers; a shuttle member slidably received in said passage means;means for imparting a forward stroke and a reverse stroke to saidshuttle member; a plurality of carrier nests associated with saidshuttle member for accommodating said articles and being spacedcomplementary to said chambers, one of said carrier nests being exposedto atmosphere at said handling end when the shuttle member is at the endof said reverse stroke for receiving unprocessed articles and fordischarging processed articles, another of carrier nests being in saidprocessing chamber when the shuttle member is at the end of said forwardstroke for presenting the unprocessed articles to a processingoperation; transfer means associated with the shuttle member andoperable after said forward stroke to shift unprocessed articles to saidchambers and simultaneously shift processed articles to said carriernests, said means being operable after said reverse stroke to shift saidprocessed articles to said chambers and simultaneously shift unprocessedarticles to said carrier nests, whereby said unprocessed articles aresequentially moved between chambers to said processing chamber duringsaid forward stroke and processed articles removed therefrom in reversesequence during said reverse stroke for discharge at said handling end.

5. An air-to-air vacuum processing machine for applying a reflectivecoating for headlamp reflectors, comprising: a vacuum enclosure having aplurality of longitudinally aligned holding chambers; a work processingstation in the holding chamber at one end of said enclosure; a reflectorhandling station at the other end of the enclosure; vacuum pumping meansfluidly connected to each of said chambers for providing a series ofcontrolled environments having progressively increasing vacuums in thedirection of said work processing station; a longitudinal passage insaid enclosure extending from said reflector handling station to saidwork processing station; a cylindrical transfer shuttle slidablyreceived in said passage for bidirectional longitudinal movement; meansoperably connected between the enclosure and the transfer shuttle forreciprocating the latter between a retracted position and an extendedposition; a plurality of transverse carrier nests formed in saidtransfer shuttle and adapted for transporting said reflectors, saidcarrier nests being longitudinally spaced complementary to said chamberswith said one of said carrier nests registering with said reflectorhandling station at said retracted position and another of said carriernests registering with said work processing station at said extendedposition, said shuttle including intermediate carrier nests registeringwith successive chambers at said shuttle positions; first transfercarriage means at said reflector handling station and operativetransversely with respect to said transfer shuttle at said retractedposition to shift reflectors to and from the carrier nest; support meansin each of said holding chambers adapted to receive and storereflectors; second transfer carriage means in said holding chambers andoperative transversely with respect to said transfer shuttle at both ofsaid shuttle positions to shift reflectors between said holding stationsand said carrier nest thereby alternately moving coated and uncoatedreflectors into and out of the control of said transfer shuttle; a pairof coating stations at said work processing station operable to apply areflective coating to said reflectors; third transfer carriage means insaid work processing chamber and operative transversely with respect tosaid transfer shuttle at said extended position for alternately shiftingreflectors to and from said coating stations whereby coated and uncoatedreflectors are alternately shifted in reverse paths along said machine.

6. A vacuum processing machine for applying a reflective coating toheadlamp reflectors on a continuous basis, comprising: a vacuumenclosure having a plurality of serially connected longitudinallyaligned holding chambers including a terminal work processing chamber atone end thereof; vacuum pumping means fluidly connected to each of saidchambers for maintaining a series of environments having progressivelyincreasing vacuums from said handling end to said work processingchamber; a loading station and an unloading station transversely spacedat the end of said enclosure remote from said work processing chamber; aseries of longitudinally aligned openings in said enclosure defining alongitudinal passage extending from between said loading and unloadingstations to said work processing chamber; a cylindrical transfer shuttleslidably received in said passage for bidirectional longitudinalmovement relative to said chambers, an hydraulic cylinder operablyconnected between said enclosure and said transfer shuttle forreciprocating the latter between an extended position and a retractedposition; a plurality of transverse carrier nests formed in saidtransfer shuttle adapted to transport said reflec tors and beinglongitudinally spaced complementary to said chambers, wherein a carriernest at one end of the transfer shuttle registers with said loading andunloading stations at said retracted position and a carrier nest at theother end registers with said work processing chamber at said extendedposition, the intermediate carrier nests registering with successivechambers at said extended and retracted positions; a first transfercarriage slidably supported at said loading and unloading stations fortransverse movement with respect to said transfer shuttle to shift acoated reflector from the carrier nest to the unloading station and tosimultaneously shift an uncoated reflector from the loading station tothe carrier nest; drive means connected to said first transfer carriagefor translating,the latter at said retracted position and for returning{said first transfer carriage at said extended position; first andsecond support means in each of said holding chambers on opposite sidesof the transfer shuttle for receiving and temporarily storingreflectors; a second transfer carriage slidably supported in said eachof said holding chambers for transverse movement with respect to saidcarrier nests; drive means connected to said second transfer carriagefor reciprocating said transfer carriage to a first position at saidextended position for shifting uncoated reflectors to said first supportmeans and for simultaneously shifting coated reflectors from said secondsupport means to said carrier nests, said drive means reversely shiftingsaid second transfer carriage to a second position at said retractedposition for shifting uncoated reflectors to said carrier nests andcoated reflectors to said second support means; first and second coatingstations in said work processing chamber on either side of said transfershuttle operable to apply a reflective coating to said reflectors; athird transfer carriage slidably supported at said work processingchamber for trans verse reciprocal with respect to said transfershuttle; drive means for reciprocating said third transfer carriage atsaid extended position to shift uncoated reflectors to said firstcoating station from said carrier nest and simultaneously shift coatedreflectors from said second coating station to said carrier nest, saidthird transfer carriage operable at the succeeding extended position toshift uncoated reflectors to said second coating station and coatedreflectors from said first coating station whereby, during each strokeof the transfer shuttle, reflectors are alternately shifted in reversepaths toward the processing chamber for coating and toward the loadingstation for exit to atmosphere.

1. A transfer apparatus for advancing articles toward and retreatingarticles from a processing operation comprising: a support member; aplurality of stations on said support member including a handlingstation at one end and a processing station at the other end associatedwith the processing operation; a shuttle member extending between saidstations; means for moving the shuttle member between a first positionand a second position; carrier means associated with the shuttle memberfor accommodating said articles, one of said carrier means registeringwith said handling station at said first position for receivingunprocessed articles and for discharging processed articles, another ofsaid carrier means registering with said processing station at saidsecond position for discharging unprocessed articles for a processingoperation and receiving processed articles, and intermediate carriermeans alternately registering with adjacent stations at said positionsfor receiving and discharging articles; first transfer means at saidprocessing station operable at said second position to dischargeunprocessed articles from and to load processed articles on said carriermeans; second transfer means at the other of said stations, said secondtransfer means operable at said first position to discharge unprocessedarticles from and to load processed articles on said carrier nests, saidsecond transfer means operable at said second position to dischargeunprocessed articles from and to load processed articles on said carriermeans whereby unprocessed articles are alternately advanced along saidstations to said processing station during movement to said secondposition and processed articles are alternately retreated from saidprocessing station along said stations in a reversely parallel pathduring return movement to said first position.
 1. A transfer apparatusfor advancing articles toward and retreating articles from a processingoperation comprising: a support member; a plurality of stations on saidsupport member including a handling station at one end and a processingstation at the other end associated with the processing operation; ashuttle member extending between said stations; means for moving theshuttle member between a first position and a second position; carriermeans associated with the shuttle member for accommodating saidarticles, one of said carrier means registering with said handlingstation at said first position for receiving unprocessed articles andfor discharging processed articles, another of said carrier meansregistering with said processing station at said second position fordischarging unprocessed articles for a processing operation andreceiving processed articles, and intermediate carrier means alternatelyregistering with adjacent stations at said positions for receiving anddischarging articles; first transfer means at said processing stationoperable at said second position to discharge unprocessed articles fromand to load processed articles on said carrier means; second transfermeans at the other of said stations, said second transfer means operableat said first position to discharge unprocessed articles from and toload processed articles on said carrier nests, said second transfermeans operable at said second position to discharge unprocessed articlesfrom and to load processed articles on said carrier means wherebyunprocessed articles are alternately advanced along said stations tosaid processing station during movement to said second position andprocessed articles are alternately retreated from said processingstation along said stations in a reversely parallel path during returnmovement to said first position.
 2. An apparatus for processing articlescomprising: means forming a plurality of interconnected chambers andhaving an ambient handling station at one end and a pressure regulatedprocessing station at the other end; passage means extending betweensaid chambers; first transfer means slidably received in said passagemeans; means for imparting a forward stroke and a reverse stroke to saidfirst transfer means; means connected to said chambers for maintainingpredetermined pressure conditions therewithin; carrier means associatedwith said first transfer means for accommodating said articles, one ofsaid carrier means registering with said handling station at the end ofsaid reverse stroke for receiving unprocessed articles and dispensingprocessed articles, another of carrier means registering with saidprocessing station at the end of said forward stroke for presentingunprocessed articles for a processing operation and receiving processedarticles; and second transfEr means in said chambers operativelyassociated with said first transfer means, said second transfer meansbeing operable after said forward stroke to transfer unprocessedarticles to holding positions in said chambers and to transfer processedarticles to said carrier means, said second transfer means beingoperable after said reverse stroke to transfer unprocessed articles fromsaid holding positions to said carrier means and to transfer processedarticles from said carrier means to said holding positions wherebyarticles are alternately advanced for processing and unloading duringeach stroke of said first transfer means.
 3. A continuous vacuumprocessing apparatus for applying a coating to an article, comprising:an enclosure having a series of chambers; passage means defining anentrance and interconnecting said chambers; pumping means communicatingwith the chambers for evacuating the latter to a predetermined pressure;a piston member slidably supported in said passage means and extendingbetween the chambers; means for reciprocating said piston memberrelative to the chambers between an extended position and a retractedposition; a work station at a chamber remote from said entranceincluding means for applying said coating to an uncoated article;nesting means on said piston member aligned and registering with thechambers at said extended position and said retracted position, one ofsaid nesting means being exposed to atmosphere beyond said entrance atsaid retracted position for receiving thereat an uncoated article anddispensing therefrom a coated article; transfer means in said chambersoperable at said retracted position to shift coated articles from saidpiston member and shift uncoated articles onto said nesting means, saidtransfer means being operable at said extended position to shiftuncoated articles from said nesting means to said work station and tosimultaneously shift coated articles onto said nesting means, wherebyarticles are continuously routed to and from said work station duringeach movement of said piston member.
 4. A vacuum processing machine forprocessing articles on a continuous basis, comprising: an enclosurehaving an enclosed processing end and an exposed handling end; aplurality of interconnected chambers in said enclosure including aprocessing chamber at said processing end; means connected to saidchambers for maintaining a series of predetermined pressure conditionstherewithin; passage means extending through said chambers; a shuttlemember slidably received in said passage means; means for imparting aforward stroke and a reverse stroke to said shuttle member; a pluralityof carrier nests associated with said shuttle member for accommodatingsaid articles and being spaced complementary to said chambers, one ofsaid carrier nests being exposed to atmosphere at said handling end whenthe shuttle member is at the end of said reverse stroke for receivingunprocessed articles and for discharging processed articles, another ofcarrier nests being in said processing chamber when the shuttle memberis at the end of said forward stroke for presenting the unprocessedarticles to a processing operation; transfer means associated with theshuttle member and operable after said forward stroke to shiftunprocessed articles to said chambers and simultaneously shift processedarticles to said carrier nests, said means being operable after saidreverse stroke to shift said processed articles to said chambers andsimultaneously shift unprocessed articles to said carrier nests, wherebysaid unprocessed articles are sequentially moved between chambers tosaid processing chamber during said forward stroke and processedarticles removed therefrom in reverse sequence during said reversestroke for discharge at said handling end.
 5. An air-to-air vacuumprocessing machine for applying a reflective coating for headlampreflectors, comprising: a vacuum enclosure having a plurality oflongitudinally aligned holding chamberS; a work processing station inthe holding chamber at one end of said enclosure; a reflector handlingstation at the other end of the enclosure; vacuum pumping means fluidlyconnected to each of said chambers for providing a series of controlledenvironments having progressively increasing vacuums in the direction ofsaid work processing station; a longitudinal passage in said enclosureextending from said reflector handling station to said work processingstation; a cylindrical transfer shuttle slidably received in saidpassage for bidirectional longitudinal movement; means operablyconnected between the enclosure and the transfer shuttle forreciprocating the latter between a retracted position and an extendedposition; a plurality of transverse carrier nests formed in saidtransfer shuttle and adapted for transporting said reflectors, saidcarrier nests being longitudinally spaced complementary to said chamberswith said one of said carrier nests registering with said reflectorhandling station at said retracted position and another of said carriernests registering with said work processing station at said extendedposition, said shuttle including intermediate carrier nests registeringwith successive chambers at said shuttle positions; first transfercarriage means at said reflector handling station and operativetransversely with respect to said transfer shuttle at said retractedposition to shift reflectors to and from the carrier nest; support meansin each of said holding chambers adapted to receive and storereflectors; second transfer carriage means in said holding chambers andoperative transversely with respect to said transfer shuttle at both ofsaid shuttle positions to shift reflectors between said holding stationsand said carrier nest thereby alternately moving coated and uncoatedreflectors into and out of the control of said transfer shuttle; a pairof coating stations at said work processing station operable to apply areflective coating to said reflectors; third transfer carriage means insaid work processing chamber and operative transversely with respect tosaid transfer shuttle at said extended position for alternately shiftingreflectors to and from said coating stations whereby coated and uncoatedreflectors are alternately shifted in reverse paths along said machine.